The term spondylolisthesis simply means movement of one vertebra over the other. This leads to motorway as well as slip road problems and the symptoms related to it (Read About Spinal Motorways).
Xray of lumbar spine illustrating forward movement of one vertebra (outline in red) over other.
The majority of the problem lies at the tunnel level. The natural shape of the keyhole is distorted, and the nerve is trapped causing shooting leg pain. Patients with spondylolisthesis commonly present with both back and leg pain. However, some may present with only claudication leg pain, and thus it is important to understand these two symptoms (Read More).
The Tunnel or Foramen outlined in blue is a Keyhole shaped passage through which the cars (Nerve -Outlined in green) passes on its way to their destination. The tunnel collapses and gets distorted during spondylolisthesis causing entrapment of nerve (Outlined in red).
There are six types of spondylolisthesis and the symptoms are effective the same.
Isthmic or Lytic (Pars Fracture)
It is due to defect in the pars interarticularis, or in simple terms, the bridge joining the roof tiles.
CT scan of lumbar spine showing normal roof tile arrangement of facets (outlined in blue) and fracture or break at the lower tile (red arrow).
It is due to defect in the pars interarticularis, or in simple terms, the bridge joining the roof tiles. It is thought to be due to abnormal stress during childhood or adolescent (growth spurt) age. Sports involving repeated backward bending like gymnastic and cricket fast bowlers are believed to cause stress at the pars leading to fracture. These fractures with time tend to not unite and cause constant back pain.
Initially the working unit of spine is balanced by healthy disc and surroundings (Read more – Working Unit of spine), but with time this starts to fail and presents with spondylolisthesis. Many patients don’t notice any leg symptoms until later in their life and the investigation finding comes as a surprise to them.
MRI of lumbar spine illustrating forward movement of one vertebra (outline in red) over other. The disc height at this level has completely collapsed.
Degenerative
This is age-related degenerative spine changes leading to claudication leg pain. It most commonly involves L4-5 level and is not commonly associated with pars injury. As mentioned earlier, it is important to be assessed to look for other non-spinal causes of these symptoms. (Read more)
Trauma
Trauma related spondylolistheses are commonly due to high impact injury, and majority of these cases need fixation to stabilise the spine.
Pathological
Pathological fracture means a break in diseased bone i.e. infection, tumour etc.
Congenital
Rare condition due to developmental defect of the spine
Post-operative
This is secondary to previous spinal surgery.
The management option can simply be divided into non-operative and operative. The conservative or non-operative options include physiotherapy, yoga, appropriate pain killers and alternative medicine like acupuncture. The role of caudal epidural and nerve root block can be an option as a diagnostic and therapeutic role if surgery is not being considered by the patient. It is believed that injection therapy is not a cure for the condition and is thought to have a limited long-term benefit.
The operative option can be in form of a limited decompression or fusion procedure depending on the patient’s symptoms and therapeutic goal. These need to be assessed and discussed during the pre-operative consultation. The decompression procedure is primarily to address leg pain, and the principle is to clear the motorways (Read More). On the other hand, fusion procedure is aimed to address both leg and back pain symptoms (Read more). In general, the improvement is more marked in leg pain rather than back pain.